Maybe in England and other leagues there is a lack of pressure on the players. I see that the english supporter forgives a lot if his team win the match, although the team didn´t fight hard. Many spanish players in english teams talk about this.
In Spain, if players don´t work hard in a game (losing is always acceptable, but you have to fight hard), local newspapers and televisions are very critical and attack players, the fans visit, insult and make jokes to players in training days, the next game is hell in the stadium ... the pressure is terrible on the players, but a pressure to fight hard, not to win. Your players must show effort and tenacity, "die on the grass" because they cost a lot of money. If you win, ok, party now, but the main idea is that the team has to show its commitment with the supporters. The win is secondary, a possible and welcome consequence.
This may explain that six of the last eight Champions Leagues and five of the last eight Europa Leagues have spanish champions (Barça, Real, Sevilla, Atlético).